Antenna needles can be placed within or in proximity to a tumor or other undesired tissue mass and RF energy applied between the two needles. The RF energy causes ionic agitation in the tissues surrounding the antenna and results in resistive heating of the targeted tissue as the RF energy travels from the active antennae toward the negatively charged grounding antennae. Multiple needle probes require a minimum of two insertion sites. When the probes are placed in a non-parallel relationship to each other along the active antennas, the energy dispersion will be unequal along the length of the probes, with greater heating occurring proximally (closer to the physician) and less heating occurring between the most distal portions (closer to the patient). Unequal energy dispersion can lead to incomplete treatments and possible system failures as electrical resistance dips below or above an acceptable level.